What is ETL?

ETL stands for extract, transform, load. It means taking data out of source systems, converting it to agreed definitions and formats, and loading it into a warehouse or platform for analysis. IBM explains that "Through a series of business rules, ETL cleanses and organizes data to address specific business intelligence needs, such as monthly reporting".

The three steps

Extract reads the data: orders from the ERP, tickets from the scale system, tallies from production, figures from spreadsheets. Load writes the result to its destination. Between them, the middle step does the real work: converting units, mapping codes, joining records, applying definitions and flagging errors.

The middle step is where meaning is set

Every conversion rule is a business decision. Convert weight to volume with which factor? Report cost with or without freight? Date a load by when it was cut, hauled or scaled? Those rules decide what every report says. They belong to someone who understands the business as well as to whoever wrote the code.

ETL or ELT

Many modern tools reverse the last two steps: extract, load, then convert inside the warehouse. Fivetran, for example, describes its connectors as "pre-built ELT pipelines" and lists "750+ sources". In our view, the practical advantage of loading raw data first is that the conversion rules can be changed and rerun on the full history. If a business runs classic ETL and doesn't keep the raw extract, a changed rule can only apply from today.

In a timber business

In timber, each unit conversion and each mapping between species or grade codes is one of those rules, and each can be right, wrong or out of date.

What to check

Ask where the conversion rules are written, who owns them, and whether raw extracts are kept. Ask what happens to records that fail a rule, and how a rule change is recorded, so last month's report can still be explained today.

How Quarri works explains the platform as a layer over existing systems, not a migration.

Quarri is an AI-native data platform for the timber supply chain. It connects buying, production, sales and inventory for forest management, sawmill, wood products and pulp, paper and packaging operators.